Is there a thicker radiator that will mount in the stock location? Stock according to Autozone is 1 row, 30 1/2" x 15 5/16" x 5/8" core size. I've looked at the GXP radiator but it doesn't look like it has a radiator cap in the pictures. Not sure where you would add coolant on a northstar engine.

*** Moved from Forced Induction ~ Kevin ***

it might have the recovery bottle with the pressure cap on it, a lot of newer cars are like that

I'm looking for a bigger radiator because i'm trying to go to a 3.1 or 3.0 pulley on a gen V supercharger with short stack intercooler. I think a GXP radiator is out if it doesn't have a radiator cap. Thanks

So you plan on cooling the IC with the same system as engine cooling?

intercooler is separate from radiator. I want to go to higher boost so I need to be able to keep engine cool when it is hot out. 160 thermostat with fans at 165 will work great if its below 70 outside. Hotter weather I'll just get knock retard and less horsepower.

We are very familiar with KR here, I think if your intercooler is running good you will keep the charged ait temp down, obviuosly a lot of tuning will need to be done to see if any timing needs to be taken out after the smaller pulley and intercooler

If the GXP radiator comes with the pressure cap in the reserve bottle why not just switch that out too? unless the whole system is different on the N* engine

why not a 180 tstat so you can get a little better milage, even a drilled one would help out to keep it cooler

I would go in small steps like maybe the intercooler first and make sure you get all the bugs worked out and make sure you know it is working good then drop to maybe a 3.5 pulley and see if there is knock and then tune to get rid of that then drop to a 3.3 and do more tuning then eventually make it to the 3.0

have you done any tuning to the car or are you stock now?

Car is heavily modified, but I have noticed that the car is considerably faster when the car is cold, first 10 minutes of running. .7 seconds on 1/4 mile. I will probably have to get the car dyno tuned to unlock this HP all the time but being able to keep the engine cool is part of the problem.

List of Modifications

2003 Bonneville SSEI
165,000 miles
Gen V supercharger with 3.25 pulley (3.1 and 3.0)
North Star Throttle body
Custom CAI
VS Cam , comp lifter and pushrods replaced valve springs
Short stack intercooler (not enough hood clearance for 2.25 thick, I tried)
Stock injectors
3” exhaust with downpipe (restrictor in tailpipes for resonance) equivalent to 2-1/2 inch exhaust
Fuel pump rewire and voltage booster
Front ported manifold
Rear ported manifold
180 deg drilled thermostat
NGK TR6IX spark plugs
ZZP PCM

Oh I thought you were starting from stock, sorry

Definately you can do better if you do some tuning instead of a canned ZZP tune

might need some bigger injectors but you will have to scan to find out because you might be maxing out the stock ones or close to it now

I would be looking for some TOG headers too so you can get some serious flow since the rest of your valvetrain is good for now

if you are worried about KR you won't know if any timing is being pulled unless you get a tuner and scan it while you are driving, or dyno-ing

is the TB hitting the hood when you put the 2.25" IC on?

Something else to think about. There are intercooler spacers that will help prevent the intercooler from absorbing the engines heat. Pair them with an ic pump regulator so that your not heating up your intercooler coolant and that could get you the result your looking for. I've never seen this done, but it sounds good in theory.

I have a Aeroforce Intercepter scan gauge on the car and from the oxygen sensor I can tell i'm not running out of injector yet. When the car is colder the O2 goes into the 1000'* and when the car warms up 950 is max. The L67 have the 36# injectors while the L32 (gen V supercharger cars) had 32# injectors....I think.

The Aeroforce guage is telling me my car will run 13.4 @ 108 mph when cold and 14.0 @ 100 mph when hot.... the gauge doesn't account for wheel spin so these times are low.

ZZP has an intercooler pump controller but they don't recommend it for the flojet pump which I have. I made my on circuit with a couple of resistor. Pump runs on 7 or 8 volts when the engine has vacuum and 15 volts when the pressure switch closes. This helps keep the intercooler fluid cooler than the engine and only go full flow when you are under boost

When I tried going with the 2.25 intercooler I set the intercooler and supercharger on the engine and tried to shut the hood. Not even close and I didn't have the throttle body on the supercharger.
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